The present invention relates to an automation system, and more particularly to an automation system including hardware components linked via at least one bus system, and a method for accessing the functionality of the hardware components.
As an example, such an automation system may include motors, sensors, actuators, etc., which form an automatic production process in conjunction with one or more superordinate control devices. Activating the hardware components normally requires the use of a special abstraction layer connected between the control devices and the hardware components, which transmits control commands between the control device and the hardware components. Thus, when replacing or upgrading the hardware components of the automation system, aside from changing the hardware components themselves, it is also usually necessary to change or adapt the control device as well, e.g., by replacing a control program in the control device that communicates with the newly replaced hardware component.
As background, WO-97/16771 describes a universal bus system used for communication purposes in a printing or copy machine, whereby each functional unit of the device is connected to the bus system via an interface, and each interface is preferably equipped with a storage unit, in which data and information assigned to certain functional units can be stored.
A private bus system for controlling household devices is described in EP-0488178A2. In this reference, room surveillance devices, to which electrical devices are connected, are connected to a central viewing control device, from which the user can control the household devices, via the private bus system.
EP-0825740A2 describes a circuit arrangement that enables the connection of various different household devices as well as devices that are not permanently installed, in a manner that does not require manually inputting commands to initiate an activation or an effect-integration of the devices in the system.
Further, WO 97/39393 discloses that it can be useful to arrange a communications bus in between individual network-based controllers (NBC), as well between NBCs operated at different locations, in order to control and process data within an industrial system. With this configuration, data packages can be exchanged directly between the NBCs. Direct access to the storage areas of another NBC is also possible.
From Schmol J., Wird OLE FOR PROCESS CONTROL, Ein Neuer Industrie Standard? [Will OLE for Process Control (OPC) Become a New Industry Standard?], ATP 39, No. 5, pages 11-12, it is known that, on the basis of Windows based technology of, inter alia, DCOM, it is possible to use the xe2x80x9cOLE for Process Controlxe2x80x9d (OPC) specification to provide a uniform method of access and a uniform interface between user programs from the industrial sector and the office sector on the one hand, and other user programs of the automation level, such as automation systems, field devices, etc. on the other hand.
Notwithstanding the disclosures above, the present invention is based on including a component directly in the hardware components, through which function objects can be executed to access the functionality of the hardware components. This component is created in the form of a system connection unit of the present invention. The system connection unit is connected to a bus system of the automation system of the present invention, so that communication data can be transmitted from a main system to a hardware component, as well as to and from all other components linked to the bus system. Therefore, the system connection unit of the present invention eliminates the need for special transmission objects, which until now were required between an administrative system and the hardware components. In addition to eliminating such transmission objects, which can be either hardware or software components, there is also a decrease in the communication error rate, since the system connection unit is essentially based on software components. This allows the configuration of the automation system to be ascertained when replacing a hardware component or, even during the operation of the system. Moreover, there is always a direct connection to the functionality of the hardware components via the system connection unit.
One object of the present invention is to provide an operating automation system which allows for replacement of hardware components without having to functionally change the automation system.
Another object of the present invention is to provide an operating automation system which eliminates the need for special transmission objects, which until now were required between an administrative system and the hardware components of the automation system.
Yet another object of the present invention is to provide a method for accessing the functionality of hardware components of an automation system.
These and other objects are solved by providing an automation system with at least one bus connecting hardware components of the automation system. At least one of the hardware components contains a system connection unit. The system connection unit has a common interface containing a pre-defined identification for each of the hardware components, and is used for communication with an external communication partner, and for receiving and transmitting information. Further, the system communication unit includes at least one function object based on a software object as an image of a real functionality of the hardware components, whereby the function object is provided for accessing the real functionality of the hardware components via the bus system.
It is envisioned that the hardware components of the present automation system can include, among other devices, motors, sensors, and actuators. In addition, the automation system of the present invention can include an administrative system and an operating and monitoring system for accessing the function objects. The function objects of the present invention can be designed as DCOM objects, and each function object can include at least one first function object for producing a minimal functionality of one of the hardware components, at least one second function object for connecting function objects, and at least one third function object for gathering function objects located in the system processing unit and/or on remote system processing units and/or on remote computers.
Further, function objects of the present invention can be designed using DCOM (Distributed Component Object Model). DCOM is a mechanism that makes it possible to run applications distributed throughout several computers in a network. In this context, a distributed application may consist of several processes that work together to perform a task. These processes can be executed on one or several computers or system connection units. In addition, a linking object can be created by providing the second function object for influencing connections between the function objects located on remote system connection units and/or remote computers.
Also in the present invention, trouble-free access to the hardware components, without the necessity of synchronization measures, can be guaranteed in that a dynamic retrieval object is generated by the third function object when the system connection unit is accessed. The special feature of this retrieval object is to enumerate the sum of the system""s functionality. Finally, the automation system of the present invention further includes a loadable table with encoding rules, thereby ensuring a simple and effective method of providing encoding methods. This produces a so-called marshalling function of the function objects.
In a method of the present invention for accessing the functionality of hardware components of an automation system, the hardware components are connected via at least one bus system, and an identification of the hardware components is pre-defined and stored in at least one system connection unit. The system connection unit communicates with an external communication partner, and the functionality of the hardware components are accessed using function objects as images of real hardware functions.